Dental drill-tool holder



No. 249,844. Patented Nov. 22,188.1.

Inventor Mn/asses,

50mm/voe) N. PETERS. PImwLimugmpmr. washington, DI,A

UNITED STATES PATENT OFFICE.

HENRY LAURENCE, OF CHICAGO, ILLINOIS.

DENTAL DRILL-TOOL HOLDER.

SPECIFICATION forming part of Letters Patent No. 249,844, dated November22, 1881.

Application filed .Tune 29, 1880. (Model.)

To all whom tt may concern:

Be it known that I, HENRY LAURENCE, of

the city of Chicago, in the State of Illinois, have made certain new anduseful improvements in the means and method of holding and detachingdrill and other tool points from the brace or other holding device forholding them, of which the followingis a specication.

Figure l shows the form of the drill or any tool-point used. Fig. 2 is asectional view, showing the construction of the socket, with the springfor holding drill-point in position. Fig. 3 is a sectional view ofholding device, showing adiiferent View from that shown in. Fig. 2. Fig.4shows the drill in position, ready for use,

I will describe only such parts of the mechanism as are necessary toshow my improve ment.

The drill pointer tool P is made iu the form shown in Fig. 1. Aboutone-half of the drillpoint is cut away at the head, and about onehalf ofthe remainder is 'cut away, leaving a shoulder at S, Fig. l. The socketor hollow shaft wherein the drill is inserted is made to conform to thecut-away part ofthe drill-point. A slight portion of this filled spaceofthe hollow shalt is cut away, as at t, Fig. 3, which leaves a circularspace, less one-quarter of the drill P, (shown at S,) for the admissionof this shoulder S. On the half-filled space in the hollow shaft g isattached a spring, O, Figs. 2-

and 3. The drill P is inserted in the hollow shaft q, and the halved endpasses over the half-lled space in said hollow shaft, and in so doingthe spring O is compressed, and when pushed in snfhciently far the drillis turned by the pressure ofthe spring one-quarter around, thus throwingthe shoulder S, Fig. 1, into the recess t, Fig. 3, which securely locksthe drill in place while in use. In removing the drill itis turnedbackward, thus compressing the spring, and unlocks theengaging-shoulders.

It will be observed that the fastening device is confined to the hollowof the shaft, requiring no external appliances. 1t will be understoodthat it is not designed to work the drill in that direction which willcause the power of the drill to work against the spring C, this servingonly to hold the drill in position.

I claim as follows:

The hollow shaft q, having the rear end of the tube partially filled,and with the recess t and spring 0, ail arranged for the purpose ofsecuring the drill P and holding it in position, substantially as shownand described.

HENRY LAURENCE.

Witnesses:

J As. A. GoWLEs, JOSEPH A. PHELPs.

